{"id":703,"date":"2016-11-29T12:25:10","date_gmt":"2016-11-29T03:25:10","guid":{"rendered":"https:\/\/www.ag.kagawa-u.ac.jp\/charlesy\/?p=703"},"modified":"2026-01-28T09:49:20","modified_gmt":"2026-01-28T00:49:20","slug":"%e7%b5%90%e5%90%88%e9%98%bb%e5%ae%b3%e5%ae%9a%e6%95%b0ki%e3%81%ae%e8%a8%88%e7%ae%97%e5%bc%8f%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6","status":"publish","type":"post","link":"https:\/\/www.ag.kagawa-u.ac.jp\/charlesy\/2016\/11\/29\/%e7%b5%90%e5%90%88%e9%98%bb%e5%ae%b3%e5%ae%9a%e6%95%b0ki%e3%81%ae%e8%a8%88%e7%ae%97%e5%bc%8f%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6\/","title":{"rendered":"\u7d50\u5408\u963b\u5bb3\u5b9a\u6570Ki\u306e\u8a08\u7b97\u5f0f\u306b\u3064\u3044\u3066"},"content":{"rendered":"\n\n\n\n\n
\"\"<\/figure>\n\n\n\n
\n

In the world of drug discovery, where scientists are the detectives and diseases are the elusive criminals, radioligand binding assays (RLBAs) were once the Sherlock Holmes of the lab.<\/p>\n\n\n\n

\u2014 Ancellin, Nicolas, \u201cRadioligand Binding Assays: A Lost Art in Drug Discovery?\u201d.<\/a><\/p>\n<\/blockquote>\n\n\n\n

\u7814\u7a76\u5ba4\u5185\u5411\u3051\u30e1\u30e2\u3002December 24, 2025\u6539\u8a02\u3002<\/p>\n\n\n\n

\u7af6\u5408\u7d50\u5408\u8a66\u9a13\u306eIC50<\/sub>\u5024\u304b\u3089\u7d50\u5408\u963b\u5bb3\u5b9a\u6570\\(K_{\\rm i}\\)\u3092\u8a08\u7b97\u3059\u308b\u65b9\u6cd5\u3068\u3057\u3066\u306f\u3001\u3088\u304f\u77e5\u3089\u308c\u3066\u3044\u308b\u8fd1\u4f3c\u7684\u306aCheng–Prusoff\u5f0f<\/strong>\u306e\u4ed6\u306b\u3001\u53b3\u5bc6\u306aMunson–Rodbard\u5f0f<\/strong>\u304c\u3042\u308a\u307e\u3059\u3002\u307e\u305f\u3001IC50<\/sub>\u3092\u6c42\u3081\u308b\u65b9\u6cd5\u306b\u306f\u975e\u7dda\u5f62\u56de\u5e30\u3068\u7dda\u5f62\u56de\u5e30\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u65b9\u6cd5\u3067\u7d50\u5408\u963b\u5bb3\u5b9a\u6570\\(K_{\\rm i}\\)\u3092\u8a08\u7b97\u3057\u305f\u6642\u306b\u3001\u30b7\u30df\u30e5\u30ec\u30fc\u30b7\u30e7\u30f3\u306e\u771f\u306e\\(K_{\\rm i}\\)\u5024\u3068\u306e\u305a\u308c\u304c\u3069\u306e\u7a0b\u5ea6\u306a\u306e\u304b\u3092\u8abf\u3079\u307e\u3057\u305f\u3002<\/p>\n\n\n\n

\u8a08\u7b97\u306e\u30d1\u30e9\u30e1\u30fc\u30bf\u306b\u306f\u53d7\u5bb9\u4f53\u3068\u3057\u3066\u30d7\u30ed\u30c6\u30a4\u30f3\u30ad\u30ca\u30fc\u30bcC \u03b4-C1B\u30c9\u30e1\u30a4\u30f3\u3001\u653e\u5c04\u6027\u6a19\u8b58\u30ea\u30ac\u30f3\u30c9\u3068\u3057\u3066 [3<\/sup>H]phorbol 12,13-dibutyrate\uff08[3<\/sup>H]PDBu\uff09\u3092\u4f7f\u7528\u3057\u305f\u6642\u306e\u5178\u578b\u7684\u306a\u5024\u3092\u4f7f\u3044\u307e\u3057\u305f: \u53d7\u5bb9\u4f53\u7dcf\u6fc3\u5ea6\\([R]_{\\textrm T} = 3.45\\; \\textrm{nM}\\), \u653e\u5c04\u6027\u6a19\u8b58\u30ea\u30ac\u30f3\u30c9\u7dcf\u6fc3\u5ea6\\([L]_{\\textrm T} = 17\\; \\textrm{nM}\\), \u653e\u5c04\u6027\u6a19\u8b58\u30ea\u30ac\u30f3\u30c9\u306e\u53d7\u5bb9\u4f53\u306b\u5bfe\u3059\u308b\u89e3\u96e2\u5b9a\u6570\\(K_{\\textrm d} = 0.53\\; \\textrm{nM}\\)\u3002\u975e\u6a19\u8b58\u30ea\u30ac\u30f3\u30c9\u306e\u6fc3\u5ea6\u7bc4\u56f2\u306f\u3001\\(K_{\\rm i}\\) = 0.05 nM\u306e\u6642log [I<\/em>]T<\/sub> \u304c\u22129.021\u304b\u3089\u22127.457; 0.1 nM\u306e\u6642\u22129.172\u304b\u3089\u22127.459; 0.5 nM\u306e\u6642\u22128.908\u304b\u3089\u22126.987; 1 nM\u306e\u6642\u22128.454\u304b\u3089\u22126.496; 10 nM\u306e\u6642\u22127.495\u304b\u3089\u22125.500; 100 nM\u306e\u6642\u22126.500\u304b\u3089\u22124.500\u3067\u3059\uff0850%\u3092\u631f\u3080\u304a\u304a\u3088\u305d\u22120.5\u523b\u307f\u306e5\u70b9\uff09\u3002<\/p>\n\n\n\n

\u5f97\u3089\u308c\u308bIC50<\/sub>\u306e\u5024\u306f\u3001\u975e\u7dda\u5f62\u56de\u5e30\uff08\u30ed\u30b8\u30b9\u30c6\u30a3\u30c3\u30af\u95a2\u6570\u3067\u30d5\u30a3\u30c3\u30c6\u30a3\u30f3\u30b0\uff09\u3068\u7dda\u5f62\u56de\u5e30\u3068\u3067\u307b\u3068\u3093\u3069\u5dee\u306f\u3042\u308a\u307e\u305b\u3093\u3067\u3057\u305f\u3002<\/p>\n\n\n\n

\u771f\u306eK<\/em>i<\/sub>\u5024<\/strong><\/td>[I<\/em>]50<\/sub><\/strong> (nM)<\/td>\u771f\u306eIC50<\/sub><\/strong> (nM)<\/td>IC50<\/sub><\/strong> (\u975e\u7dda\u5f62\u56de\u5e30\u3001\u30ed\u30b8\u30b9\u30c6\u30a3\u30c3\u30af\u95a2\u6570)<\/td>IC50<\/sub><\/strong> (\u7dda\u5f62\u56de\u5e30)<\/td><\/tr>
0.05 nM<\/td>1.51<\/td>3.24<\/td>3.18<\/td>3.17<\/td><\/tr>
0.1 nM<\/td>3.02<\/td>4.75<\/td>4.72<\/td>4.68<\/td><\/tr>
0.5 nM<\/td>15.1<\/td>16.8<\/td>16.8<\/td>16.8<\/td><\/tr>
1 nM<\/td>30.2<\/td>31.9<\/td>31.9<\/td>31.9<\/td><\/tr>
10 nM<\/td>302<\/td>304<\/td>303<\/td>303<\/td><\/tr>
100 nM<\/td>3019<\/td>3020<\/td>3015<\/td>3014<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u771f\u306eK<\/em>i<\/sub>\u5024<\/strong><\/td>\u771f\u306eIC50<\/sub>\u304b\u3089\u8a08\u7b97\u3057\u305fK<\/em>i<\/sub>\u5024 (nM)<\/strong><\/td><\/tr>
Cheng–Prusoff<\/strong><\/td>Modified Cheng–Prusoff<\/strong>a<\/em><\/sup><\/td>Munson–Rodbard (exact) correction<\/strong><\/td>IC50<\/sub> – [R<\/em>]T<\/sub>\/2<\/strong> correction<\/strong>b<\/em><\/sup><\/td><\/tr>
0.05 nM<\/td>0.0980<\/td>0.108<\/td>0.0500<\/td>0.0502<\/td><\/tr>
0.1 nM<\/td>0.143<\/td>0.159<\/td>0.100<\/td>0.100<\/td><\/tr>
0.5 nM<\/td>0.508<\/td>0.561<\/td>0.499<\/td>0.499<\/td><\/tr>
1 nM<\/td>0.964<\/td>1.07<\/td>1.00<\/td>1.00<\/td><\/tr>
10 nM<\/td>9.19<\/td>10.2<\/td>10.0<\/td>10.0<\/td><\/tr>
100 nM<\/td>91.3<\/td>101<\/td>100<\/td>100<\/td><\/tr><\/tbody>
a<\/em><\/sup> [L<\/em>]T<\/sub> \u306e\u4ee3\u308f\u308a\u306b [L<\/em>]50<\/sub> \u3092\u4f7f\u7528\u3057\u3066\u8a08\u7b97\u3057\u305f\u3002 
b<\/sup><\/em> \\(K_{\\mathrm i} = (\\mathrm{IC}_{50} – [R]_\\mathrm{T}\/2 )\/(2 [L]_{50}\/[L]_{0} – 1 + [L]_{50}\/K_\\mathrm{d}) \\).<\/td><\/tr><\/tfoot><\/table><\/figure>\n\n\n\n

\u5206\u304b\u3063\u305f\u3053\u3068:<\/p>\n\n\n\n